The present invention relates to a seismic source, in particular a down-hole seismic source, comprising an actuator. The present invention further relates to a method of generating a seismic wave in a formation.
A down-hole seismic source is described in U.S. Pat. No. 4,702,343. This down-hole seismic source is provided with a vibrator body in the form of a clamping plate which is brought into contact with an inside wall of a subterranean bore hole by means of radially directed pistons. The pistons are operated by means of a hydraulic fluid. In order to excite a seismic wave, the clamping force exerted by the pistons can be varied in a pulsating mode by operating a servo control valve that actuates the pistons. The servo control valve is controlled by a signal and power from surface passing through an electric line, for generation of which signal an electric oscillator is required.